Metal container adapted to receive



w. couPET-rE ET AL Re. 24,936 METAL CONTAINER ADAFTED TO RECEIVEHIGH-MELTING POIIN'I1 LIQUID METALS Feb. 14, 1961 2 Sheets-Sheet 1`Original Filed Dec.

6 3 uw 4 2 a R Feb. 14, 1961 w. couPETTE ET AL METAL CONTAINER ADAPTEDTo RECEIVE:

HIGH-MELTING POINT LIQUID METALS s. 1954 2 Sheets-Sheet 2 Original FiledDeo.

Fig?

United States Patent O METAL CONTAINER ADAPTED T RECEIVE HIGH-MELTINGPOINT LIQUID METALS Werner Coupette, Adolf Sickbert, and Rudolf Westib,

Wattenscheid, Germany, assignors to Leybold-Hochvakuum-Anlagen,G.m.b.H., Koln-Bayental, Germany Original No. 2,784,961, dated Mar. 12,1957, Ser. No. 472,978, Dec. 3, 1954. Application for reissue Feb. 3,1959, Ser. No. 790,994

Claims priority, application Germany Dec. 5, 1953 3 Claims. (Cl.2615-42) Matter enclosed in heavy brackets appears in the originalpatent but forms no part of this reissue speeltication; matter printedin italics indicates the additions made by reissue.

The present invention relates to the treatment of highmelting pointmolten metals, e.g. steel, by withdrawing undesired gas therefrom or bybringing the molten metal in contact with desired gases in order toimprove the properties of the metal. For this purpose, a vessel is used,which, on the one hand, is adapted to be evacuated, and which, on theother hand, is provided with means for introducing gas. The molten metalis poured into the evacuated vessel through a hole in the lid thereof,and to this end a pouring ladle with a discharge hole in its bottom isplaced on the lid of the evacuated vessel, so that the liquid metal canbe transferred from the pouring ladle into the evacuated vessel. Thepouring ladle rests on the lid of the evacuated vessel, and the seat ofthe pouring ladle is air-tightly sealed in order to prevent air frompassing into the evacuated vessel, or gas from escaping into theatmosphere.

The pouring ladle is formed by a container suited to receive thehigh-melting point liquid metal, and it consists to this end of an outermetal shell provided with a lining of refractory material, and a nozzleis provided in the bottom of the container. The nozzle is formed by abody of ceramic material with a central bore therein, and it is insertedinto the refractory lining and projects out of the metal shell.

It has been found that during the transfer of the liquid metal from thecontainer into the evacuated vessel the vacuum therein deteriorates, inspite of a perfect seal between the bottom of the said liquid-metalcontainer and. the lid of the evacuated vessel, and it has beenascertained that this is due to the fact that air passes throughunavoidable interspaces between the metal shell and the lining of theliquid-metal container, and even through the material `of the liningitself. Moreover, a loss of gas has been ascertained, if it was desired,which is possible with the `arrangement of this kind, to introduce gasunder pressure from the lower vessel into the upper liquid-metalcontainer.

It is therefore the object of the present invention to overcome theabove mentioned ditliculties, and particularly to stop the passage ofgas through the unavoidable leakage paths in the wall of theliquid-metal container.

To this end a liquidmetal container suited to receive high-melting-pointliquid metal, which comprises an outer metal shell, an interior liningfor the metal shell which lining consists or" a refractory material, abody of ceramic material inserted into the bottom of the said interiorlining and projecting through the outer metal shell which body has anopening formed therein, is characterized in that a shield consisting ofsheet metal is arranged so as to surround the said ceramic body and hastwo rims, the one rim being connected by welding to the inner face ofthe metal shell While the other rim projects into the interior of thecontainer so as to extend into the liquid metal when the liquid-metalcontainer is in operation. Thus nice the air or the gas, -as the casemay be, is stopped from passing through the small leakage channels, andthe process of treating the metal can be controlled in a more reliablemanner than hitherto.

The invention will be explained in more detail with reference to theaccompanying drawings, wherein- Fig. 1 represents a metal containerwhich rests on the lid of an evacuated vessel suited for a vacuumtreatment of the liquid metal,

Fig. 2 shows a construction of the shield which surrounds the ceramicbody in the bottom of the refractory interior lining,

Figs. 3 and 4 illustrate on an enlarged scale two details of thearrangement according to Fig. 2, and

Fig. 5 represents another embodiment of the invention.

Fig. 1 indicates the application of the invention to a metal containerwith a refractory interior lining (both shown in section), the metalcontainer resting on a vacuurn vessel. The metal container 10 consistsof a metal shell 11 and of a refractory interior lining 12 consisting ofa ceramic material, for instance tire-brick. A body 13 of ceramicmaterial, having a nozzle 14, is inserted into the bottom of theinterior lining 12 and into the bottom of the metal shell 11. Aso-called stopper rod 15, which is adapted to be moved in a verticaldirection, serves for closing the said nozzle. The whole metal container10 rests on the vacuum vessel 17, the seat being sealed by means of asuitable `sealing ring 16. The lid 18 of the vacuum vessel has anopening 19 through which the liquid metal jet can pass. The lid 18 isair-tightly connected with the vessel 20 by means of another ring-shapedseal 21. Into the lateral wall of the vessel 20 a pipe 22 opens whichleads to a vacuum pump and comprises a valve 23. Another pipe 24 opensinto the lateral wall of the evacuated vessel 20 to which a pressuremeasuring device or a vacuum measuring device 25 of suitableconstruction is connected and which also is equipped with a valve Z6.The pipe 24 leads through the valve 26 to a reservoir for the desiredgas. A conventional pouring ladle 28 rests upon a stone floor 27 withinthe vacuum vessel 20.

For the vacuum treatment of the steel pouring from the container 10 intothe pouring ladle 28, the vacuum vessel 17 is evacuated through the pipe22 by the vacuum pump so that any gases escaping from theliquid steelare Withdrawn by the vacuum pump. In this case the valve 26 is closed.However, it is also possible to bring the liquid steel into contact withcertain desirable gases by opening of the valve 26. Moreover, the pipe24 may also be used for a comparatively quick and complete removal ofgases, which escape from the liquid steel when the latter solidifeswithin the pouring ladle 28, in such a manner that air or a suitable gasis supplied into the vessel 17 through the pipe 24 andis again Withdrawnthrough the pipe 22 by the vacuum pump.

It will now be explained in more detail with reference to Fig. 2 howundesirable air can enter into the vacuum vessel if steel isvacuum-treated with an arrangement according to Fig. l, and how such apenetration of air into the vacuum vessel can be prevented by means of ashield according to the invention. Fig. 2 shows a section of a part ofthe bottom -of the metal shell 11 of the container 10, and also therefractory interior lining 12 resting on the bottom 11, and finally thehereinbefore mentioned ceramic body 13, which is inserted into theinterior lining and into the bottom. This ceramic body, which may alsobe made of tire-brick, is provided with the hereinbefore mentionedopening 14 into which another ceramic body 29 is inserted which has achannel 30 which is adapted to be closed by the rod 15 shown in Fig. l.The body 29 with its channel 30 is held within the body 13 by means of aring 31 which is connected to the bottom 11 by means of screws.

If the liquid steel passes from the container 10 through the opening 14and the channel 30 into the vacuum vessel 17, then there is a dangerthat a certain quantity of air enters at the upper yrim of thecontainer10 into the interspace between the interior lining 12 and the lateralwall of the metal container 11, which air then advances also between theinterior lining 12 and the bottom l11, shown in Fig. 2, up to theceramic body 13 and then enters be tween the lower side of the body 13and the bottom 11 into the evacuated vessel 17. In order to block thispath for the air, a shield 32 consisting of thin sheet metal is arrangedaccording to the invention so that it surrounds the ceramic body 1 3,which shield is connected by welding at its lower rim with the bottom 11and extends with its upper rim into the liquid metal. This shield 32prevents not only the penetration of air into the vacuum vessel 17 alongthe path hereinbefore mentioned, but it also prevents the entry into thevacuum vessel of any air which may penetrate by diffusion through thematerial of the refractory interior lining 12 and through [through] thewall of the ceramic body 13 as well as through the wall of the ceramicbody 29 into the channel 30.

The portion of Fig. 2 surrounded by a circle 33, is represented on anenlarged scale in Fig. 3. This figure shows again the refractoryinterior lining 12, the ceramic body 13 and the shield 32, and it can beseen that the interspace between the shield 32, the interior lining 12and the ceramic body 13 is filled with a refractory mortar 34.

The portion off Fig. 2, surrounded by a circle 3S, is represented on anenlarged scale in Fig. 4, which shows again the interior lining 12, theceramic body 13, the screening surface 32, and the refractory mortar 34,and indicates that the lower rim of the shield is welded to the bottom11 of the metal container by means of a sheet metal ring 36 which has agreater thickness than the sheet metal 32. The welding points are markedby 37 and 38.

Thus it is possible by the arrangement of the described sheet metalshield 32 to prevent safely air from entering into the evacuated vessel17 when the liquid metal is transferred from the container 10 into thepouring ladle 28.

If it is desired to supply to the liquid metal within the container 10certain gases through the opening 14 shown in Figs. 1 and 2 and throughthe channel 30, then it is possible with an arrangement according toFig. 1 to close the valve 23 after the vessel 17 has been evacuated, andto lill the vessel through the open valve 26 with the desired gas and atthe same time to produce within the vessel such an excess pressure thatthe desired gas, after the rod 15 has been lifted, enters into theliquid metal through the channel 30 and the opening 14. If there were nosheet metal shield 32, then part of the gas could escape in a directionopposite to the direction of the entering air as describedhere'inbefore. Such a loss of gas is completely avoided by the provisionof the said sheet metal shield 32, and it is ensured that all thesupplied gas actually enters the metal.

By loosening the screws by means of which the ring 31 is fastened -tothe bottom 11 of the metal container it is easily possible to exchangethe interior ceramic body 29 after each pouring operation so that theopening 14 yand the channel 30 can be always tightly closed by means ofthe rod [13] 1.5.

Another construction of the sheet metal shield will be explained withreference to Fig. 5. In Fig. 5 the evacuated vessel 17 and the seal 16are represented only schematically, and the metal container has the formof a conventional pouring ladle. Also in this case the metal containerconsists of an outer shell 11 and of an interior refractory lining 12.The ceramic body 13 `and the rod 15 have not been shown, since they arenot required for the rexplanation of the construction of the sheet metalshield. The sheet metal shield may be given, as represented at 39, theshape of a sheet metal ring, the outer rim of which being welded to theinternal face of the metal wall 11, whilst its outer rim projects intothe liquid metal, the level of which is indicated by a chain dotted line40. Also in lthis case a sheet metal ring 41, the inner rim of whichprojects into the liquid metal, may be connected by welding to astronger sheet metal ring 42, and the latter may be connected by weldingto the inner face of the metal wall 11, i.e. a construction may beadopted similar to that shown in Fig. 4.

The` ring 39` yand the ring 41 must be disposed always below the level40 of the liquid metal similarly as the sheet metal 32 of Fig. 2 inorder to prevent air from entering into the vacuum vessel 17 as well asa loss of gas which it is desired to introduce into the liquid metal.

Having now fully described our invention, what we claim as new anddesire to secure by Letters Patent is:

1. A liquid-metal container suited to receive highmelting-point liquidmetal, comprising an outer metal shell having an interior lining ofrefractory material, a body of ceramic material inserted into the bottomof the said interior lining and projecting through the outer metal shellwhich body has an opening formed therein, yand a shield consistin-g ofsheet metal which surrounds the said ceramic body 'and has two rims, onerim of which is connected [by welding] gas-tightly to the inner face ofthe metal shell, while the other rim projects into the space of thecontainer reserved for the liquid metal so that said metal shield willextend into the liquid metal when said container is in operation.

2. A liquid-metal container according to claim 1, wherein a metal ringsurrounds the rim of the shield adjacent to themetal shell, and whereinthe metal ring is connected by welding to the metal shell and the saidrim of the shield is connected by welding to the metal ring.

3. An arrangement for subjecting liquid metal to a gastreatment,comprising a vessel air-tightly closed by a lid, which vessel is adaptedto be evacuated, is provided with means for the supply-of gas, and has ahole in its lid and suited to receive high-melting point liquid metal;and a liquid metal container comprising an outer metal shell having aninterior lining of refractory material, la body of ceramic materialhaving an opening formed therein, and inserted rinto the bottom of thesaid interior lining and projecting through said outer metal shell and ashield consisting of sheet metal which surrounds the said ceramic bodyand has two rims, one rim of which is connected [by welding] gas-tightlyto the inner face of the metal shell, while the other rim projects intothe space of the container reserved for the liquid metal so that saidmetal shield will extend into the liquid metal when said container is inoperation; said liquid-metal container being placed above the lid of thevessel so that the opening in the said ceramic body comes to lie abovethe said hole in the lid, and means being provided for air-tightlyconnecting the bottomof the .said liquid-metal container with the lid ofthe said vessel so as to prevent access of air to the said hole.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 1,674,947 Bunce et al .Tune 26, 1928 1,889,426Stout Nov. 29, 1932 2,134,248 Godenne Oct. 25, 1938 2,134,785 GoldbergNov. 1, 1938 2,230,141 Heuer Jan. 28, 1941 2,253,421 De Mare Aug. 19,1941 2,416,490 Molique Feb. 25, 1947 2,462,699 Wilcox Feb. 22, 19492,631,836 Willis Mar. 17, 1953 2,665,895 Herman Jan. 12, 1954 FOREIGNPATENTS 1,056,554 France Oct. 21, 1953

